<template>
  <!-- 筛选区 -->
  <div class="sub-filter" v-if="filterData && !filterLoading">
    <div class="item">
      <div class="head">品牌：</div>
      <div class="body">
        <a @click="changeBrand(brand.id)" :class="{active:filterData.selectedBrand===brand.id}" href="javasript:;"
          v-for="brand in filterData.brands" :key="brand.id">{{brand.name}}</a>
      </div>
    </div>
    <div class="item" v-for="item in filterData.saleProperties" :key="item.id">
      <div class="head">{{item.name}}：</div>
      <div class="body">
        <a v-for="attr in item.properties" @click="changeProp(item,attr.id)"
          :class="{active:item.selectedProp===attr.id}" href="javasript:;" :key="attr.id">{{attr.name}}</a>
      </div>
    </div>
  </div>
  <div v-else class="sub-filter">
    <XtxSkeleton class="item" width="800px" height="40px" />
    <XtxSkeleton class="item" width="800px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
  </div>
</template>
<script>
import { findSubCategoryFilter } from '@/api/category'
import { useRoute } from 'vue-router'
import { ref, watch } from 'vue'
export default {
  name: 'SubFilter',
  setup(props, { emit }) {
    // 1. 获取数据
    // 2. 数据中需要全部选中，需要预览将来点击激活功能。默认选中全部
    // 3. 完成渲染
    // 4. 分类发生变化的时候需要重新获取筛选数据，需要使用侦听器
    const route = useRoute()
    const filterData = ref(null)
    const filterLoading = ref(false)
    watch(() => route.params.id, async (newVal) => {
      //当你从二级分类去顶级分类也会拿到ID，不能去加载数据因为它不是二级分类的ID
      if (newVal && route.path === ('/category/sub/' + newVal)) {
        filterLoading.value = true
        let { result } = await findSubCategoryFilter(route.params.id)
        // 品牌全部
        result.selectedBrand = null
        result.brands.unshift({ id: null, name: '全部' })
        // 销售属性全部
        result.saleProperties.forEach(p => {
          p.selectedProp = undefined
          p.properties.unshift({ id: null, name: '全部' })
        })
        filterData.value = result
        filterLoading.value = false
      }
    }, { immediate: true })
    // 获取筛选参数的函数
    const getFilterParams = () => {
      const obj = {
        brandId: null,
        attrs: []
      }
      // 品牌
      obj.brandId = filterData.value.selectedBrand
      // 销售属性
      filterData.value.saleProperties.forEach(item => {
        // 如果当前行有值
        if (item.selectedProp) {
          // 找到有值的属性
          const prop = item.properties.find(prop => prop.id === item.selectedProp)
          obj.attrs.push({ groupName: item.name, propertyName: prop.name })
        }
      })
      if (obj.attrs.length === 0) obj.attrs = null
      return obj
    }

    // 品牌改变
    const changeBrand = (brandId) => {
      if (filterData.value.selectedBrand === brandId) return
      filterData.value.selectedBrand = brandId
      emit('filter-change', getFilterParams())
    }
    // 筛选区改变
    const changeProp = (item, propId) => {
      if (item.selectedProp === propId) return
      item.selectedProp = propId
      emit('filter-change', getFilterParams())

    }
    return {
      filterData, filterLoading, changeBrand, changeProp
    }
  }
}
</script>
<style lang="less" scoped>
// 筛选区
.sub-filter {
  background: #fff;
  padding: 25px;
  .item {
    display: flex;
    line-height: 40px;
    .head {
      width: 80px;
      color: #999;
    }
    .body {
      flex: 1;
      a {
        margin-right: 36px;
        transition: all 0.3s;
        display: inline-block;
        &.active,
        &:hover {
          color: @xtxColor;
        }
      }
    }
  }
}
.xtx-skeleton {
  padding: 10px 0;
}
</style>